Telephone-exchange testing system



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y UNITEDISTATES mrl-:N'rv omer..

JOHN B. RETALLACX, or EA'sToRANGE, NEW rERsEmAssIGNoE To WESTERN ELEC- Tmc COMPANLTNCORPORATED, oETNEW YoRK, N. Y., A CORPORATION or NEW YORK.

Application led May 9,

To all whom t may concern.'

Be it` known that I, JOHN B. RETALLAGK, a citizen of the United States of America, residing at East Orange, in the county of Essex, State of New-Jersey, have invented certain new and useful Improvements in Telephone-Exchange Testing Systems,` of which the following is a full, clear, concise, and exact description.

This invention relates to a telephone exchange system, and more particularly to a testing system for use in a manual oflice interconnecting with automatic offices.

It is an object of this invention to provide an improved testing system;

In exchange areas that .include both manual and automatic oiiices, it is desirable to extend'calls originating in the manual office to subscribers in the automatic office. In some exchange areas of this type, the manual ollice is equipped with common apparatus to be set by an operator therein for controlling the automaticselection of an idle trunk to 'any automatic `office and for the control of the selective switches of the automatic oice over the selected trunk. The trunk number is indicated to' the operator by the lighting of lamps and the calling plug of a cord circuit is inserted in the trunk of that number in the standard manner of completing a manual connection. The subscriber who has access tothe manual ofiice is thus quickly connected to any subscriber whose line terminates in an automatic office.

It is necessary for each manual operator to care for a large number of outgoing calls extendingv to both manual and automatic subscribers and it is apparent that the ordinary method of using a dial for the controlof selective switches would be slow and reduce the number of calls handled by an TELEPHONE-EXCHANGE TESTING SYSTEM.

1924. serial No. 711,970.

that eliicientservice `may be given to the telephone subscribers.

A .feature of this invention is in the provision of a sender testing unit to establish control circuits foi-.operating the registers of sender and consecutively setting said registers upon one continuous revolution of a switch.r l y t A further feature of this invention is in the provision of a testing unit to test a link whose ordinary function is to select outgoing trunks to automatic exchanges and to select a sender for controlling` rautomatic switches over said trunk.

A further feature of this inventionA is in the provision of a testing unit rto control arbitrarily trunk indicating f apparatus which is ordinarily functioned by the automatic selection of an idle trunk.

These and other features of the invention will be rapparent from the following description taken in connection with the accompanying drawings. v l

-While the invention has been disclosed as particularlyadapted for testing apparatus associated with manual and panel type machine switching oices, it is apparent from the following description that the invention has a wider utility and that by slight modifications it could be adapted for testing other types of apparatus. I

Referring to the accompanying drawings, Figs. l to 6 illustrate testing equipment for testing the apparatus and circuits shown in Figs. 7 to 16.

Fig. l illustrates a testing unit for testing the operation of trunk indicating apparatus shown in Fig. 9.

Figs. 2 and 3 illustrate a testing unit for testing v the link in conjunction with the sender apparatus shown in Figs. 7 and 10 to 16 inclusive. f

Figs. 4, 5 and 6 illustrate a testing unit for testing the sender apparatus shown in Figs. llll, l5 and 16.V f Figs. 7 to 16, inclusive, illustrate a switching mechanism arranged for .the extension of calls from a manual office to an automatic oHice controlled from va manual switchboard position. This system is described in detail in the patent to Louis M. Allen, No. 1,513,- 362, issuedoct. 28, 1924. f

Fig'. 17Y illustrates the manner in which olf' the ,testing system with regard to their numbering sequence.

Description of apparatus.

Referring to the apparatus used in F igs.

1 to 6, inclusive, the switch shown at 670, in Fig. 6, some of its cams being shown on both Figs.'4 and 6is of the sequence switch type. The switch shown `in Fig. is of the selfinterrupting step-by-step type. Keys 409 to 439, inclusive, Vare of the manual locking type. Keys 109 and 119, inclusive, shown in Fig. 1, are also of the manual locking tylipe.` Keys 380`to 389 inclusive, in'Fig. 3 are ot' the non-locking type. The remain,- der oi' the apparatus `is of a type well known, which will be referred to in the detailed description.

Delia/Zed description.

Assuming that the sender portion of the key indicator system, is to be tested by the apparatus ofFigs. 4, 5 and 6, a testman operates key 630 to associate brushes 603, 604, 605 and 606 with cams and key contacts shown in Fig. 4. Key 630 remains locked during the test. -Key 633 is now operated and. released. The operation of key 633 establishes fr circuit to energize switch magnet 600. This circuit may be traced from grounded battery through the winding of magnet 600, contacts of key 633, right normal contact of key 631, upper contacts of cam 612, right normal contact of relay V644, right outer `normal contacts of relay 642 Ato ground. Theenergization of magnet 600 attracts its armature in such manner that, when key 633 is Vreleased to deenergize Lmagnet 600, the brush assembly 601 to 606 is stepped forward to the irst position terminals, to associate thev testing equipment with conductors 660 to 665, inclusive, connected to the first senderto be tested. Following the advance of the brush assembly 601 to 606, inclusiye, keyr631 is operated and remains locked during the test. The operation` of key l631 establishes an energizing circuit for relay 645. This circuit may be traced from grounded battery through the left winding of relay 645, left inner normal cont-acts4 of relay 642l to ground through the left contact of key 631. A ground circuit is also establishedfrom the lett outer contact of key 631,- through the conductor 655, left outer normal contacts of relay 543, conductor 654, to the armatures oi' relays 641 and 640. VThis ground circuit is later used as a locking path for relays 640 and 641. The operation of i relay 645 establishes an obvious circuit to relay 643 to cause its release.

operate relay 643. The operation of relay 643 establishes a circuit to operate relay 642. This circuit may be traced from grounded battery `throu'h the winding of relay 642, let't contact ci relay 643 Vto ground through the left contact of key 631. Relay 642in operating establishes a locking circuit for itself through its left 'inner contact to `ground through the left contact of key 631.

The operation of relay 643 'further establishes a circuit `from grounded battery through the right winding of relay 645, right contact of` relay 643, left contact of key 630, brush 606 and its associated contact, conductor 665, to conductor v1324 of 'the sender torbetested. If this sender is busy, conductor 1324 is characterized by .ground potential which will maintain rela-y 645 in an operated position. It' the sender is idle or becomes idle during the association of 4the test circuit with the sender, conductor 1324 is not characterizedA by a ground potential and relay 645 is released. The release of relay 4645 Lopens the actuatingcircuit for The release of relayn643 associates ground potential with brush 606 to characterize the sender as busy and to establish'an operating circuit for relay 1401,. This circuit may be traced from ground through the right inner contacts of relay 642 right normal contact of relay 643, lett contact of key 630, brush 606 and its associated contact, conductor 665, conductor 1324 and thence to grounded battery through resistance1402 and relay 1401 operating relay 1401. Thecircuit paths established by the operation of relay 1401 will be described later. The operation of relay 642 further establishes a circuit to light lamp 635 as an indication that the sender to be tested is not busy. This circuit may be tracedl from grounded battery through lamp 635, left outer Contact of relay 642, left normal contact rof relay 643 to ground through the left contact of key 631.

A registration on keys 400 to 439, inclusive, is now made to establish circuits for the operation of certain of the register relays shown in Fig. 16. One of keys 400 to 409, inclusive, is operated for controlling incoming brush selection. One of keys 410 to 419, inclusive, is operated for linal brush selection. The incoming group selection is dependenton the combination of the aforesaid keys along with the operation or nonoperation of relay 450. One of keys 420 to 429, inclusive, is operated for nal tens se lection and one of keys 430 to 439, inclusive, is operated for final units selection. All ot' keys 400 lto 439, inclusive, are of `the lock` ing type and the circuit paths remain established through their contacts to operate the register' relays upon the rotation of the sequence switch cams shown in Fig. 4. lVhen the registration keys have been set, start key 441 is actuated to establish an operating circuit fora-relay 640 which is obvious and need not be traced. The operation of relay 640 establishes a circuitl to energize sequence switch vmagnet 610. This vcircuit may be traced from grounded battery through the winding of magnet 610, contact ot'rcam 611, left normal contact of relay 641, left contact of `relay 640, leiftfoutercontact ofv relay 642, left normal contact of relay to ground-through the left contacts or key 631. The sequence switch cams make a complete revolution since master contact 67 0 is established `in all positions except position 1. Upon the rotation of the sequence switch, circuits are progressively established to control the sender and operate the various sets of register relays, as will be described later.

The operation otrelay 640 further establishes a circuit to operate relays 644 and545. The energizing .circuit for relay 644 may be traced from grounded battery through its winding, left contact of relay 640, left outer contact of relay 642, letnormal contactof relay-643 to ground' through the left contacts of key 631. The operating circuit for relay 545 maybe traced from grounded battery. through its winding the left back contact of relay 547, conductor 658, and thence to ground over the operating circuit traced for relay 644. A circuit is also established from/this ground through brush 505 and its associated contact, lamp 530 to grounded battery to light lamp 530 as an indication that brush assemblyA 501 to 506, inclusive, is resting in its normalposition.Y The operation of relay 644 opens at its right contacts, the actuating circuitA for magnet 600 to prevent further operationy of switch magnet 600, since key 631 mighty be released pre,- vious to the completion ot` the test of the sender.

Assuming that thegcall number registered on keys 401.to 439, inclusive is 1647 the testman has actuated key 401, key 416, key 424 and key 437. Upon the rotation of the sequence switch to position 4, the circuit established through the contacts of key 401 becomes eective and may be traced from ground throughl the upper Contact of cam 622, resistance 444, right inner contacts of key 401, lettupper contact of cam 618, contact of cam 614, conductor 651, right middle contact of key 630, brush 604, conductor 663, conductor 1415, brush 1412 andi its associated contact, conductor 1416, left windings oi relays 1602, and 1603 conductor 1613 to grounded battery at theV middle left Y contact of relay 1403, relay 1403 having op erated yupon the prior operation .of relay 1401. Relay 1602 operates in this circuit but f due to the inclusionof resistance 444, the marginal relay 1603 remains inert.'4 Relay 1602 locks inI4 a .circuitl lromfgroiuid' through its inner right contacttand right winding to battery on conductor 1613. Another circuit is completed from ground through the upper contact ot cam 622, left inner contacts of key 401, left inner contacts of key 401, left upper contact of cam "f tobattery on conductor 1613. Since no resistance is included in this circuit, the marn ginal4V register relay 1601 operates and locks from ground through its inner left contact and left winding in series with 'its right winding. y Relay 1600 is also energized in a circuit from grounded battery on conductor 1613, right winding of relay 1600, inner rightcontact of relay 1601, inner right contact of relay 1602 to ground. Relay 1404 which becomes energized completes a circuit from ground through its contact, left nor mal contact oi relay 1407, right normal contact otrelayV 1400, contact andwvindiiig of stepping magnet 1408 to grounded batte-ry. Relay 1406, which is energized in parallel with the stepping magnet, closesa locking .circuit ior itself including the contact of magnet 1608 and also closes aholdingcircuit for magnet 1608 independent of the contact relay 1604. The magnet 1608 becomes energized and 'when its armature is fully attracted, the circuit of' relay 1406 is opened and the relaybecomes deenergized to open the circuit of magnet 1408. Magnet 1408 releases and advances the brushes of the register control switch forward one step.

When brushes 1409 to 1414, inclusive, of the register control switch reach position 1, a circuit is closed from grounded battery throughthe winding of relay 1503, left normal contacts of relay 1502, conductor 1516,

brush 1409 to ground. Relay 1503 operates and closes a circuit from ground through its inner left contact, conductor 1517 and thence in parallel through the resistance 1402 and winding of relay 1401 to grounded battery. f y Upon the further rotation of the sequence switch 670 to position 5, circuits are established through the contacts of key 416. A circuit isthus established from the ground through the upper' contact of cam 622, re` sistance 444, right inner contacts of key 416, right upper contact of cam 618,'contact of cam 614, conductor 651, right middle contacts of key 630, brush 604 and its associated contact, conductor 663, conductor 1415,

`brush 1412 and its associated contact, conductor 1418, leftwinding of relay 1605, left winding of relay'1606 to grounded battery on conductor 1613. Relay 1605 operates and locks throughits right winding but the relay 1606 gis.; marginal Yand remains unoper,

ated. Another circuit is established from ground through the upper contact of cam 622, left inner contacts of `key 416, left upper contact of cam/616, contactioi'cam 613, conductor 650, right inner contact oi' key 630, brush 605 and its associated contact, conductor-664, winding of relay 1405, brush 1410, conductor 1419,.-right winding of relay '1604, to grounded battery on conductor 1613. Relay y1604 operates and locks through its inner left contact and both winding in series. Relay 1405 is also energized to cause the .advance of the register control switch inthe -mannerrabove described from position 1 to .position l2. Relay 1405 further establishes Aa circuit from -vground through its contact, normal contact of relay 1404, brush 141.4, `conductor 1420, right winding of relay 1607 Ato grounded battery on conductor 1613. Relay 1607 operates and looks through its left winding and left contact.

Upon further rotation of the sequence switchto position 6, circuits are. `established through the contacts of key 424. A circuit is established from ground, through vthe lower left contact .of cam 622, left Contact of key 442, right inner-.contacts of :key 424, right lower contact of cam 619, cam 614, conductor 651, right middle .contacts of key 630, brush 604 andits associatedcontact conductor .663, lconductor 1415, brush y1412 and its associated contact, conductor 1421, left winding of relay 1614, left winding of relay 1609, conductor 1615, inner left contact of `relay 1403 to grounded battery. Relays 1614 and 1609 operateand lockthroughtheir right windings. Another circuit is established 'from ground through the lower left lcontact of cam 622, lett contactof key 442, resistance 443, left contact of key 424, lright lower contact of cam 621, contact of cam 61'5, conductor 652, right outer contact of key` 630, brush 603 and its associated contact, conductor 662, winding of relay 1404, brush 1410, conductor 1422, right winding of relay 1608, conductor 1613 to grounded battery. Relay 1404 operates in the circuit traced. Relay 1608 is marginal and remains inactive. Inthe manner previously'described, the relay 1404 establishes a circuit to advance the register control switch to -its third position.

Upon further `rotation of sequence sw-itch 670, to position 7, circuits are established through the contacts of key A436. A circuit is established from ground through the lower left contact of cam 622, left contact of key 442, left contact of key 636, right lower contact of cam 617, contact of -cam 613, conductor 650, right inner contacts of key 630, brush 605 and its associated contact, conductor 664, winding of relay l1405 brush 1410 and its associatedcontact, conductor 1423, right Winding of relay 1610, conductor 1615 to grounded battery.4 Relay 16.10 operates over `the circuit itraced and locks through both of its windings. Relay 1405 operates and establishes a circuit through its contact and the normal Contact or' relay 1404, brush 1414, and its associated contact, conductor 1424, right winding of relay 1612, conductor 1615 `to `grounded battery. Relay 1612 operates in ythe `circuit traced and locks through its left winding and left contact. Relay 1405 establishes `a circuit to advance the brush assembly of the register 'control switch from position 3 to position 4. When brush 1409 of the control switch is advanced from .position 3, the previously traced circuit of relay 1503 is opened and the vrelay deenergized. At the time that relay 1503 operates following the registration of the lirst digit, acircuit is established from battery through the stepping magnet 1513 of V4the sender control switch, contact of said magnet, outer left contact of rela-y,1503, to ground through brush 1509 audits associated contact. Nagnet 1513 interrupts its own circuit and advances the brushes of the sender control switch to their Zero position terminals, which is the first position-of `the switch. In lthis position, the fundamental circuit is established between `the sender and the testing circuit. Under ordinary operating conditions this fundamental circuit is established through a selective switch to control brush selection. The fundamental circuit may be traced from `grounded battery through the winding ot relay 547 brush 506 and its associated contact, left inner contacts of Arelay 544, left outer'contacts o'l' relay 644, brush 602 and its associated contact, conductor 661, brush 1507 and its associated contact, windings of stepping relay 1500, left winding of over- Aflow relay 1506, left contacts of the 0 counting relay conductors 1518 and 660, brush 601 and its associated contact, lleft innercontact ot relay 644, conductor 657, right inner contact of relay 544, resistance 511 to ground. Stepping relay 1500 and relay 547 operate in the fundamental circuit traced. The effect of the operation of the stepping relay will be described later. The operation of relay 547 establishes a circuit to energize test switch magnet 500. This circuit may be traced from grounded battery through the winding of magnet 500, brush 504'and its associated contact, left contact-of relay 547, left contacts of relay 640, left outer contact o1 relay 642, left normal con tact of lrelay 643 to ground through the left contacts of key 631. The test switch brush assembly 501 to 506 inclusive, know rotates from position 1 to position 2, and the energizing circuit for magnet 500 is opened upon the rotation of the switch. In the second position of the switch a locking circuit is establish-ed 4for relay 547 which may be traced from grounded battery through its 

